Rob Kardashian, 25, took to Twitter to seemingly call out his reported girlfriend (and presumably now ex) Rita Ora, 22, for cheating.

"She cheated on me with nearly 20 dudes while we were together, I wonder how many she will sleep with now that we apart? But I mean 20?!!!," he just tweeted. "How can a woman who is so busy trying to start her own career have time to be with so many dudes all while in a relationship?!"

After month of rumors, Rob publicly confirmed in October that they were dating , when he posted a kissing pic of the two together on Twitter. In August, he posted a photo of his and Rita's knuckles tattooed with each other's names. "S--- got crazy tonight… What can I say… #tatmynameonya," he tweeted.